Incidence of response and long-term follow-up in patients with hairy cell leukemia treated with recombinant interferon alfa-2a.
Thirty-five evaluable patients with hairy cell leukemia (HCL) were treated with recombinant interferon alfa-2a (rIFN-alpha 2a), given at a dose of 3 X 10(6) units (U) intramuscularly (IM) daily for 6 months followed by 3 X 10(6) U IM three times a week for an additional 18 months in a single institution study. All treatment was stopped after 24 months. Sixty-nine percent of patients achieved a partial response, 11% a minor response, and 3% (one patient) had stable disease. Six patients (17%) did not respond to rIFN-alpha 2a. Two patients (6%) achieved a response but later progressed on treatment. A total of 23 patients completed 2 years of treatment and are evaluable for long-term follow-up at a median of 20 months postcompletion of therapy (range 9 to 32 months). Eleven patients (48%) have had progression of their disease at a median of 10 months (range .5 to 25 months) after treatment was discontinued. Statistical analysis of pretreatment patient characteristics did not reveal any factor(s) associated with a high probability of responding to rIFN-alpha 2a; however, analysis of post-treatment variables measured after 2 years of treatment suggested that a low platelet count was associated with a high rate of disease progression. These findings are compared with other published trials using rIFN-alpha 2b, a similar but not identical rIFN preparation. We conclude that while rIFN-alpha 2a has a high overall response incidence, the rate of disease progression after therapy is discontinued approaches 50%, and that a subset of patients can be identified who are at high risk for recurrence after completing 2 years of treatment.
Berman
E
E
Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.
Heller
G
G
Kempin
S
S
Gee
T
T
Tran
L L
LL
Clarkson
B
B
D000328:Adult; D000368:Aged; D000917:Antibody Formation; D004305:Dose-Response Relationship, Drug; D004341:Drug Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007273:Injections, Intramuscular; D007370:Interferon Type I / Q000276:immunology / Q000627:therapeutic use* / Q000633:toxicity; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage / Q000627:therapeutic use* / Q000633:toxicity; D007943:Leukemia, Hairy Cell / Q000188:drug therapy* / Q000453:epidemiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011994:Recombinant Proteins
D007370:Interferon Type I; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins